// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
 * Copyright (C) STMicroelectronics SA 2017
 *
 * Modified by Philippe Cornu <philippe.cornu@st.com>
 * This generic Synopsys DesignWare MIPI DSI host driver is based on the
 * Rockchip version from rockchip/dw-mipi-dsi.c with phy & bridge APIs.
 */

#include <linux/clk.h>
#include <linux/component.h>
#include <linux/debugfs.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>

#include <video/mipi_display.h>

#include <drm/bridge/dw_mipi_dsi.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_modes.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>

#define HWVER_131 0x31333100 /* IP version 1.31 */

#define DSI_VERSION 0x00
#define VERSION GENMASK(31, 8)

#define DSI_PWR_UP 0x04
#define RESET 0
#define POWERUP BIT(0)

#define DSI_CLKMGR_CFG 0x08
#define TO_CLK_DIVISION(div) (((div)&0xff) << 8)
#define TX_ESC_CLK_DIVISION(div) ((div)&0xff)

#define DSI_DPI_VCID 0x0c
#define DPI_VCID(vcid) ((vcid)&0x3)

#define DSI_DPI_COLOR_CODING 0x10
#define LOOSELY18_EN BIT(8)
#define DPI_COLOR_CODING_16BIT_1 0x0
#define DPI_COLOR_CODING_16BIT_2 0x1
#define DPI_COLOR_CODING_16BIT_3 0x2
#define DPI_COLOR_CODING_18BIT_1 0x3
#define DPI_COLOR_CODING_18BIT_2 0x4
#define DPI_COLOR_CODING_24BIT 0x5

#define DSI_DPI_CFG_POL 0x14
#define COLORM_ACTIVE_LOW BIT(4)
#define SHUTD_ACTIVE_LOW BIT(3)
#define HSYNC_ACTIVE_LOW BIT(2)
#define VSYNC_ACTIVE_LOW BIT(1)
#define DATAEN_ACTIVE_LOW BIT(0)

#define DSI_DPI_LP_CMD_TIM 0x18
#define OUTVACT_LPCMD_TIME(p) (((p)&0xff) << 16)
#define INVACT_LPCMD_TIME(p) ((p)&0xff)

#define DSI_DBI_VCID 0x1c
#define DSI_DBI_CFG 0x20
#define DSI_DBI_PARTITIONING_EN 0x24
#define DSI_DBI_CMDSIZE 0x28

#define DSI_PCKHDL_CFG 0x2c
#define CRC_RX_EN BIT(4)
#define ECC_RX_EN BIT(3)
#define BTA_EN BIT(2)
#define EOTP_RX_EN BIT(1)
#define EOTP_TX_EN BIT(0)

#define DSI_GEN_VCID 0x30

#define DSI_MODE_CFG 0x34
#define ENABLE_VIDEO_MODE 0
#define ENABLE_CMD_MODE BIT(0)

#define DSI_VID_MODE_CFG 0x38
#define ENABLE_LOW_POWER (0x3f << 8)
#define ENABLE_LOW_POWER_MASK (0x3f << 8)
#define VID_MODE_TYPE_NON_BURST_SYNC_PULSES 0x0
#define VID_MODE_TYPE_NON_BURST_SYNC_EVENTS 0x1
#define VID_MODE_TYPE_BURST 0x2
#define VID_MODE_TYPE_MASK 0x3
#define ENABLE_LOW_POWER_CMD BIT(15)
#define VID_MODE_VPG_ENABLE BIT(16)
#define VID_MODE_VPG_MODE BIT(20)
#define VID_MODE_VPG_HORIZONTAL BIT(24)

#define DSI_VID_PKT_SIZE 0x3c
#define VID_PKT_SIZE(p) ((p)&0x3fff)

#define DSI_VID_NUM_CHUNKS 0x40
#define VID_NUM_CHUNKS(c) ((c)&0x1fff)

#define DSI_VID_NULL_SIZE 0x44
#define VID_NULL_SIZE(b) ((b)&0x1fff)

#define DSI_VID_HSA_TIME 0x48
#define DSI_VID_HBP_TIME 0x4c
#define DSI_VID_HLINE_TIME 0x50
#define DSI_VID_VSA_LINES 0x54
#define DSI_VID_VBP_LINES 0x58
#define DSI_VID_VFP_LINES 0x5c
#define DSI_VID_VACTIVE_LINES 0x60
#define DSI_EDPI_CMD_SIZE 0x64

#define DSI_CMD_MODE_CFG 0x68
#define MAX_RD_PKT_SIZE_LP BIT(24)
#define DCS_LW_TX_LP BIT(19)
#define DCS_SR_0P_TX_LP BIT(18)
#define DCS_SW_1P_TX_LP BIT(17)
#define DCS_SW_0P_TX_LP BIT(16)
#define GEN_LW_TX_LP BIT(14)
#define GEN_SR_2P_TX_LP BIT(13)
#define GEN_SR_1P_TX_LP BIT(12)
#define GEN_SR_0P_TX_LP BIT(11)
#define GEN_SW_2P_TX_LP BIT(10)
#define GEN_SW_1P_TX_LP BIT(9)
#define GEN_SW_0P_TX_LP BIT(8)
#define ACK_RQST_EN BIT(1)
#define TEAR_FX_EN BIT(0)

#define CMD_MODE_ALL_LP                                                                                                \
    (MAX_RD_PKT_SIZE_LP | DCS_LW_TX_LP | DCS_SR_0P_TX_LP | DCS_SW_1P_TX_LP | DCS_SW_0P_TX_LP | GEN_LW_TX_LP |          \
     GEN_SR_2P_TX_LP | GEN_SR_1P_TX_LP | GEN_SR_0P_TX_LP | GEN_SW_2P_TX_LP | GEN_SW_1P_TX_LP | GEN_SW_0P_TX_LP)

#define DSI_GEN_HDR 0x6c
#define DSI_GEN_PLD_DATA 0x70

#define DSI_CMD_PKT_STATUS 0x74
#define GEN_RD_CMD_BUSY BIT(6)
#define GEN_PLD_R_FULL BIT(5)
#define GEN_PLD_R_EMPTY BIT(4)
#define GEN_PLD_W_FULL BIT(3)
#define GEN_PLD_W_EMPTY BIT(2)
#define GEN_CMD_FULL BIT(1)
#define GEN_CMD_EMPTY BIT(0)

#define DSI_TO_CNT_CFG 0x78
#define HSTX_TO_CNT(p) (((p)&0xffff) << 16)
#define LPRX_TO_CNT(p) ((p)&0xffff)

#define DSI_HS_RD_TO_CNT 0x7c
#define DSI_LP_RD_TO_CNT 0x80
#define DSI_HS_WR_TO_CNT 0x84
#define DSI_LP_WR_TO_CNT 0x88
#define DSI_BTA_TO_CNT 0x8c

#define DSI_LPCLK_CTRL 0x94
#define AUTO_CLKLANE_CTRL BIT(1)
#define PHY_TXREQUESTCLKHS BIT(0)

#define DSI_PHY_TMR_LPCLK_CFG 0x98
#define PHY_CLKHS2LP_TIME(lbcc) (((lbcc)&0x3ff) << 16)
#define PHY_CLKLP2HS_TIME(lbcc) ((lbcc)&0x3ff)

#define DSI_PHY_TMR_CFG 0x9c
#define PHY_HS2LP_TIME(lbcc) (((lbcc)&0xff) << 24)
#define PHY_LP2HS_TIME(lbcc) (((lbcc)&0xff) << 16)
#define MAX_RD_TIME(lbcc) ((lbcc)&0x7fff)
#define PHY_HS2LP_TIME_V131(lbcc) (((lbcc)&0x3ff) << 16)
#define PHY_LP2HS_TIME_V131(lbcc) ((lbcc)&0x3ff)

#define DSI_PHY_RSTZ 0xa0
#define PHY_DISFORCEPLL 0
#define PHY_ENFORCEPLL BIT(3)
#define PHY_DISABLECLK 0
#define PHY_ENABLECLK BIT(2)
#define PHY_RSTZ 0
#define PHY_UNRSTZ BIT(1)
#define PHY_SHUTDOWNZ 0
#define PHY_UNSHUTDOWNZ BIT(0)

#define DSI_PHY_IF_CFG 0xa4
#define PHY_STOP_WAIT_TIME(cycle) (((cycle)&0xff) << 8)
#define N_LANES(n) (((n)-1) & 0x3)

#define DSI_PHY_ULPS_CTRL 0xa8
#define DSI_PHY_TX_TRIGGERS 0xac

#define DSI_PHY_STATUS 0xb0
#define PHY_STOP_STATE_CLK_LANE BIT(2)
#define PHY_LOCK BIT(0)

#define DSI_PHY_TST_CTRL0 0xb4
#define PHY_TESTCLK BIT(1)
#define PHY_UNTESTCLK 0
#define PHY_TESTCLR BIT(0)
#define PHY_UNTESTCLR 0

#define DSI_PHY_TST_CTRL1 0xb8
#define PHY_TESTEN BIT(16)
#define PHY_UNTESTEN 0
#define PHY_TESTDOUT(n) (((n)&0xff) << 8)
#define PHY_TESTDIN(n) ((n)&0xff)

#define DSI_INT_ST0 0xbc
#define DSI_INT_ST1 0xc0
#define DSI_INT_MSK0 0xc4
#define DSI_INT_MSK1 0xc8

#define DSI_PHY_TMR_RD_CFG 0xf4
#define MAX_RD_TIME_V131(lbcc) ((lbcc)&0x7fff)

#define PHY_STATUS_TIMEOUT_US 10000
#define CMD_PKT_STATUS_TIMEOUT_US 20000

#ifdef CONFIG_DEBUG_FS
#define VPG_DEFS(name, dsi) ((void __force *)&((*dsi).vpg_defs.name))

#define REGISTER(name, mask, dsi)                                                                                      \
    {                                                                                                                  \
#name, VPG_DEFS(name, dsi), mask, dsi                                                                          \
    }

struct debugfs_entries {
    const char *name;
    bool *reg;
    u32 mask;
    struct dw_mipi_dsi *dsi;
};
#endif /* CONFIG_DEBUG_FS */

struct dw_mipi_dsi {
    struct drm_bridge bridge;
    struct mipi_dsi_host dsi_host;
    struct drm_bridge *panel_bridge;
    struct device *dev;
    void __iomem *base;

    struct reset_control *apb_rst;

    unsigned int lane_mbps; /* per lane */
    u32 channel;
    u32 lanes;
    u32 format;
    unsigned long mode_flags;

#ifdef CONFIG_DEBUG_FS
    struct dentry *debugfs;
    struct debugfs_entries *debugfs_vpg;
    struct {
        bool vpg;
        bool vpg_horizontal;
        bool vpg_ber_pattern;
    } vpg_defs;
#endif /* CONFIG_DEBUG_FS */

    struct dw_mipi_dsi *master; /* dual-dsi master ptr */
    struct dw_mipi_dsi *slave;  /* dual-dsi slave ptr */

    const struct dw_mipi_dsi_plat_data *plat_data;
};

/*
 * Check if either a link to a master or slave is present
 */
static inline bool dw_mipi_is_dual_mode(struct dw_mipi_dsi *dsi)
{
    return dsi->slave || dsi->master;
}

/*
 * The controller should generate 2 frames before
 * preparing the peripheral.
 */
static void dw_mipi_dsi_wait_for_two_frames(const struct drm_display_mode *mode)
{
    int refresh, two_frames;

    refresh = drm_mode_vrefresh(mode);
    two_frames = DIV_ROUND_UP(MSEC_PER_SEC, refresh) * 0x2;
    msleep(two_frames);
}

static inline struct dw_mipi_dsi *host_to_dsi(struct mipi_dsi_host *host)
{
    return container_of(host, struct dw_mipi_dsi, dsi_host);
}

static inline struct dw_mipi_dsi *bridge_to_dsi(struct drm_bridge *bridge)
{
    return container_of(bridge, struct dw_mipi_dsi, bridge);
}

static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 val)
{
    writel(val, dsi->base + reg);
}

static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
{
    return readl(dsi->base + reg);
}

static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device)
{
    struct dw_mipi_dsi *dsi = host_to_dsi(host);
    const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
    struct drm_bridge *bridge;
    struct drm_panel *panel;
    int max_data_lanes = dsi->plat_data->max_data_lanes;
    int ret;

    dsi->lanes = (device->lanes > max_data_lanes) ? device->lanes / 0x2 : device->lanes;
    dsi->channel = device->channel;
    dsi->format = device->format;
    dsi->mode_flags = device->mode_flags;

    ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel, &bridge);
    if (ret) {
        return ret;
    }

    if (panel) {
        bridge = drm_panel_bridge_add_typed(panel, DRM_MODE_CONNECTOR_DSI);
        if (IS_ERR(bridge)) {
            return PTR_ERR(bridge);
        }
    }

    dsi->panel_bridge = bridge;

    drm_bridge_add(&dsi->bridge);

    if (pdata->host_ops && pdata->host_ops->attach) {
        ret = pdata->host_ops->attach(pdata->priv_data, device);
        if (ret < 0) {
            return ret;
        }
    }

    return 0;
}

static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host, struct mipi_dsi_device *device)
{
    struct dw_mipi_dsi *dsi = host_to_dsi(host);
    const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
    int ret;

    if (pdata->host_ops && pdata->host_ops->detach) {
        ret = pdata->host_ops->detach(pdata->priv_data, device);
        if (ret < 0) {
            return ret;
        }
    }

    drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);

    drm_bridge_remove(&dsi->bridge);

    return 0;
}

static void dw_mipi_message_config(struct dw_mipi_dsi *dsi, const struct mipi_dsi_msg *msg)
{
    bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
    u32 val = 0;

    /*
     * dw drv improvements
     * largest packet sizes during hfp or during vsa/vpb/vfp
     * should be computed according to byte lane, lane number and only
     * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
     */
    dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(16) | INVACT_LPCMD_TIME(4));

    if (msg->flags & MIPI_DSI_MSG_REQ_ACK) {
        val |= ACK_RQST_EN;
    }
    if (lpm) {
        val |= CMD_MODE_ALL_LP;
    }

    dsi_write(dsi, DSI_CMD_MODE_CFG, val);

    val = dsi_read(dsi, DSI_VID_MODE_CFG);
    if (lpm) {
        val |= ENABLE_LOW_POWER_CMD;
    } else {
        val &= ~ENABLE_LOW_POWER_CMD;
    }
    dsi_write(dsi, DSI_VID_MODE_CFG, val);
}

static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
{
    int ret;
    u32 val, mask;

    ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, !(val & GEN_CMD_FULL), 0x3e8,
                             CMD_PKT_STATUS_TIMEOUT_US);
    if (ret) {
        dev_err(dsi->dev, "failed to get available command FIFO\n");
        return ret;
    }

    dsi_write(dsi, DSI_GEN_HDR, hdr_val);

    mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
    ret =
        readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, (val & mask) == mask, 0x3e8, CMD_PKT_STATUS_TIMEOUT_US);
    if (ret) {
        dev_err(dsi->dev, "failed to write command FIFO\n");
        return ret;
    }

    return 0;
}

static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi, const struct mipi_dsi_packet *packet)
{
    const u8 *tx_buf = packet->payload;
    int len = packet->payload_length, pld_data_bytes = sizeof(u32), ret;
    __le32 word;
    u32 val;

    while (len) {
        if (len < pld_data_bytes) {
            word = 0;
            memcpy(&word, tx_buf, len);
            dsi_write(dsi, DSI_GEN_PLD_DATA, le32_to_cpu(word));
            len = 0;
        } else {
            memcpy(&word, tx_buf, pld_data_bytes);
            dsi_write(dsi, DSI_GEN_PLD_DATA, le32_to_cpu(word));
            tx_buf += pld_data_bytes;
            len -= pld_data_bytes;
        }

        ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, !(val & GEN_PLD_W_FULL), 0x3e8,
                                 CMD_PKT_STATUS_TIMEOUT_US);
        if (ret) {
            dev_err(dsi->dev, "failed to get available write payload FIFO\n");
            return ret;
        }
    }

    word = 0;
    memcpy(&word, packet->header, sizeof(packet->header));
    return dw_mipi_dsi_gen_pkt_hdr_write(dsi, le32_to_cpu(word));
}

static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi, const struct mipi_dsi_msg *msg)
{
    int i, j, ret, len = msg->rx_len;
    u8 *buf = msg->rx_buf;
    u32 val;

    /* Wait end of the read operation */
    ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, !(val & GEN_RD_CMD_BUSY), 0x3e8,
                             CMD_PKT_STATUS_TIMEOUT_US);
    if (ret) {
        dev_err(dsi->dev, "Timeout during read operation\n");
        return ret;
    }

    for (i = 0; i < len; i += 0x4) {
        /* Read fifo must not be empty before all bytes are read */
        ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, !(val & GEN_PLD_R_EMPTY), 0x3e8,
                                 CMD_PKT_STATUS_TIMEOUT_US);
        if (ret) {
            dev_err(dsi->dev, "Read payload FIFO is empty\n");
            return ret;
        }

        val = dsi_read(dsi, DSI_GEN_PLD_DATA);
        for (j = 0; j < 0x4 && j + i < len; j++) {
            buf[i + j] = val >> (0x8 * j);
        }
    }

    return ret;
}

static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, const struct mipi_dsi_msg *msg)
{
    struct dw_mipi_dsi *dsi = host_to_dsi(host);
    struct mipi_dsi_packet packet;
    int ret, nb_bytes;

    ret = mipi_dsi_create_packet(&packet, msg);
    if (ret) {
        dev_err(dsi->dev, "failed to create packet: %d\n", ret);
        return ret;
    }

    dw_mipi_message_config(dsi, msg);
    if (dsi->slave) {
        dw_mipi_message_config(dsi->slave, msg);
    }

    ret = dw_mipi_dsi_write(dsi, &packet);
    if (ret) {
        return ret;
    }
    if (dsi->slave) {
        ret = dw_mipi_dsi_write(dsi->slave, &packet);
        if (ret) {
            return ret;
        }
    }

    if (msg->rx_buf && msg->rx_len) {
        ret = dw_mipi_dsi_read(dsi, msg);
        if (ret) {
            return ret;
        }
        nb_bytes = msg->rx_len;
    } else {
        nb_bytes = packet.size;
    }

    return nb_bytes;
}

static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
    .attach = dw_mipi_dsi_host_attach,
    .detach = dw_mipi_dsi_host_detach,
    .transfer = dw_mipi_dsi_host_transfer,
};

static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
{
    u32 val;

    /*
     * dw drv improvements
     * enabling low power is panel-dependent, we should use the
     * panel configuration here...
     */
    val = ENABLE_LOW_POWER;

    if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
        val |= VID_MODE_TYPE_BURST;
    } else if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
        val |= VID_MODE_TYPE_NON_BURST_SYNC_PULSES;
    } else {
        val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;
    }

#ifdef CONFIG_DEBUG_FS
    if (dsi->vpg_defs.vpg) {
        val |= VID_MODE_VPG_ENABLE;
        val |= dsi->vpg_defs.vpg_horizontal ? VID_MODE_VPG_HORIZONTAL : 0;
        val |= dsi->vpg_defs.vpg_ber_pattern ? VID_MODE_VPG_MODE : 0;
    }
#endif /* CONFIG_DEBUG_FS */

    dsi_write(dsi, DSI_VID_MODE_CFG, val);
}

static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi, unsigned long mode_flags)
{
    u32 val;

    dsi_write(dsi, DSI_PWR_UP, RESET);

    if (mode_flags & MIPI_DSI_MODE_VIDEO) {
        dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
        dw_mipi_dsi_video_mode_config(dsi);
    } else {
        dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
    }

    val = PHY_TXREQUESTCLKHS;
    if (dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
        val |= AUTO_CLKLANE_CTRL;
    }
    dsi_write(dsi, DSI_LPCLK_CTRL, val);

    dsi_write(dsi, DSI_PWR_UP, POWERUP);
}

static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
{
    const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;

    if (phy_ops->power_off) {
        phy_ops->power_off(dsi->plat_data->priv_data);
    }

    dsi_write(dsi, DSI_PWR_UP, RESET);
    dsi_write(dsi, DSI_PHY_RSTZ, PHY_RSTZ);
    pm_runtime_put(dsi->dev);
}

static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
{
    const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
    unsigned int esc_rate; /* in MHz */
    u32 esc_clk_division;
    int ret, value;

    /*
     * The maximum permitted escape clock is 20MHz and it is derived from
     * lanebyteclk, which is running at "lane_mbps / 8".
     */
    if (phy_ops->get_esc_clk_rate) {
        ret = phy_ops->get_esc_clk_rate(dsi->plat_data->priv_data, &esc_rate);
        if (ret) {
            DRM_DEBUG_DRIVER("Phy get_esc_clk_rate() failed\n");
        }
    } else {
        esc_rate = 0x14; /* Default to 20MHz */
    }

    /*
     * We want :
     *     (lane_mbps >> 3) / esc_clk_division < X
     * which is:
     *     (lane_mbps >> 3) / X > esc_clk_division
     */
    value = esc_rate + 1;
    if (value == 0) {
        return;
    }
    esc_clk_division = (dsi->lane_mbps >> 0x3) / value;

    dsi_write(dsi, DSI_PWR_UP, RESET);

    /*
     * dw drv improvements
     * timeout clock division should be computed with the
     * high speed transmission counter timeout and byte lane...
     */
    dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVISION(0xa) | TX_ESC_CLK_DIVISION(esc_clk_division));
}

static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi, const struct drm_display_mode *mode)
{
    u32 val = 0, color = 0;

    switch (dsi->format) {
        case MIPI_DSI_FMT_RGB888:
            color = DPI_COLOR_CODING_24BIT;
            break;
        case MIPI_DSI_FMT_RGB666:
            color = DPI_COLOR_CODING_18BIT_2 | LOOSELY18_EN;
            break;
        case MIPI_DSI_FMT_RGB666_PACKED:
            color = DPI_COLOR_CODING_18BIT_1;
            break;
        case MIPI_DSI_FMT_RGB565:
            color = DPI_COLOR_CODING_16BIT_1;
            break;
    }

    if (mode->flags & DRM_MODE_FLAG_NVSYNC) {
        val |= VSYNC_ACTIVE_LOW;
    }
    if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
        val |= HSYNC_ACTIVE_LOW;
    }

    dsi_write(dsi, DSI_DPI_VCID, DPI_VCID(dsi->channel));
    dsi_write(dsi, DSI_DPI_COLOR_CODING, color);
    dsi_write(dsi, DSI_DPI_CFG_POL, val);
}

static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
{
    dsi_write(dsi, DSI_PCKHDL_CFG, CRC_RX_EN | ECC_RX_EN | BTA_EN);
}

static void dw_mipi_dsi_video_packet_config(struct dw_mipi_dsi *dsi, const struct drm_display_mode *mode)
{
    /*
     * dw drv improvements
     * only burst mode is supported here. For non-burst video modes,
     * we should compute DSI_VID_PKT_SIZE, DSI_VCCR.NUMC &
     * DSI_VNPCR.NPSIZE... especially because this driver supports
     * non-burst video modes, see dw_mipi_dsi_video_mode_config()...
     */

    dsi_write(dsi, DSI_VID_PKT_SIZE,
              dw_mipi_is_dual_mode(dsi) ? VID_PKT_SIZE(mode->hdisplay / 0x2) : VID_PKT_SIZE(mode->hdisplay));
}

static void dw_mipi_dsi_command_mode_config(struct dw_mipi_dsi *dsi)
{
    /*
     * dw drv improvements
     * compute high speed transmission counter timeout according
     * to the timeout clock division (TO_CLK_DIVISION) and byte lane...
     */
    dsi_write(dsi, DSI_TO_CNT_CFG, HSTX_TO_CNT(0x3e8) | LPRX_TO_CNT(0x3e8));
    /*
     * dw drv improvements
     * the Bus-Turn-Around Timeout Counter should be computed
     * according to byte lane...
     */
    dsi_write(dsi, DSI_BTA_TO_CNT, 0xd00);
    dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
}

/* Get lane byte clock cycles. */
static u32 dw_mipi_dsi_get_hcomponent_lbcc(struct dw_mipi_dsi *dsi, const struct drm_display_mode *mode, u32 hcomponent)
{
    u32 lbcc;

    lbcc = hcomponent * dsi->lane_mbps * MSEC_PER_SEC / 0x8;

    if (mode->clock == 0) {
        DRM_ERROR("dsi mode clock is 0!\n");
        return 0;
    }

    return DIV_ROUND_CLOSEST_ULL(lbcc, mode->clock);
}

static void dw_mipi_dsi_line_timer_config(struct dw_mipi_dsi *dsi, const struct drm_display_mode *mode)
{
    u32 htotal, hsa, hbp, lbcc;

    htotal = mode->htotal;
    hsa = mode->hsync_end - mode->hsync_start;
    hbp = mode->htotal - mode->hsync_end;

    /*
     * dw drv improvements
     * computations below may be improved...
     */
    lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, htotal);
    dsi_write(dsi, DSI_VID_HLINE_TIME, lbcc);

    lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hsa);
    dsi_write(dsi, DSI_VID_HSA_TIME, lbcc);

    lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hbp);
    dsi_write(dsi, DSI_VID_HBP_TIME, lbcc);
}

static void dw_mipi_dsi_vertical_timing_config(struct dw_mipi_dsi *dsi, const struct drm_display_mode *mode)
{
    u32 vactive, vsa, vfp, vbp;

    vactive = mode->vdisplay;
    vsa = mode->vsync_end - mode->vsync_start;
    vfp = mode->vsync_start - mode->vdisplay;
    vbp = mode->vtotal - mode->vsync_end;

    dsi_write(dsi, DSI_VID_VACTIVE_LINES, vactive);
    dsi_write(dsi, DSI_VID_VSA_LINES, vsa);
    dsi_write(dsi, DSI_VID_VFP_LINES, vfp);
    dsi_write(dsi, DSI_VID_VBP_LINES, vbp);
}

static void dw_mipi_dsi_dphy_timing_config(struct dw_mipi_dsi *dsi)
{
    const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
    struct dw_mipi_dsi_dphy_timing timing;
    u32 hw_version;
    int ret;

    ret = phy_ops->get_timing(dsi->plat_data->priv_data, dsi->lane_mbps, &timing);
    if (ret) {
        DRM_DEV_ERROR(dsi->dev, "Retrieving phy timings failed\n");
    }

    /*
     * dw drv improvements
     * data & clock lane timers should be computed according to panel
     * blankings and to the automatic clock lane control mode...
     * note: DSI_PHY_TMR_CFG.MAX_RD_TIME should be in line with
     * DSI_CMD_MODE_CFG.MAX_RD_PKT_SIZE_LP (see CMD_MODE_ALL_LP)
     */

    hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
    if (hw_version >= HWVER_131) {
        dsi_write(dsi, DSI_PHY_TMR_CFG,
                  PHY_HS2LP_TIME_V131(timing.data_hs2lp) | PHY_LP2HS_TIME_V131(timing.data_lp2hs));
        dsi_write(dsi, DSI_PHY_TMR_RD_CFG, MAX_RD_TIME_V131(0x2710));
    } else {
        dsi_write(dsi, DSI_PHY_TMR_CFG,
                  PHY_HS2LP_TIME(timing.data_hs2lp) | PHY_LP2HS_TIME(timing.data_lp2hs) | MAX_RD_TIME(0x2710));
    }

    dsi_write(dsi, DSI_PHY_TMR_LPCLK_CFG, PHY_CLKHS2LP_TIME(timing.clk_hs2lp) | PHY_CLKLP2HS_TIME(timing.clk_lp2hs));
}

static void dw_mipi_dsi_dphy_interface_config(struct dw_mipi_dsi *dsi)
{
    /*
     * dw drv improvements
     * stop wait time should be the maximum between host dsi
     * and panel stop wait times
     */
    dsi_write(dsi, DSI_PHY_IF_CFG, PHY_STOP_WAIT_TIME(0x20) | N_LANES(dsi->lanes));
}

static void dw_mipi_dsi_dphy_init(struct dw_mipi_dsi *dsi)
{
    /* Clear PHY state */
    dsi_write(dsi, DSI_PHY_RSTZ, PHY_DISFORCEPLL | PHY_DISABLECLK | PHY_RSTZ | PHY_SHUTDOWNZ);
    dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
    dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_TESTCLR);
    dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
}

static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
{
    u32 val;
    int ret;

    dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK | PHY_UNRSTZ | PHY_UNSHUTDOWNZ);

    ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val, val & PHY_LOCK, 0x3e8, PHY_STATUS_TIMEOUT_US);
    if (ret) {
        DRM_ERROR("failed to wait phy lock state\n");
    }

    ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val, val & PHY_STOP_STATE_CLK_LANE, 0x3e8,
                             PHY_STATUS_TIMEOUT_US);
    if (ret) {
        DRM_ERROR("failed to wait phy clk lane stop state\n");
    }
}

static void dw_mipi_dsi_clear_err(struct dw_mipi_dsi *dsi)
{
    dsi_read(dsi, DSI_INT_ST0);
    dsi_read(dsi, DSI_INT_ST1);
    dsi_write(dsi, DSI_INT_MSK0, 0);
    dsi_write(dsi, DSI_INT_MSK1, 0);
}

static void dw_mipi_dsi_bridge_post_disable(struct drm_bridge *bridge)
{
    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);

    /*
     * Switch to command mode before panel-bridge post_disable &
     * panel unprepare.
     * Note: panel-bridge disable & panel disable has been called
     * before by the drm framework.
     */
    dw_mipi_dsi_set_mode(dsi, 0);
    if (dsi->slave) {
        dw_mipi_dsi_set_mode(dsi->slave, 0);
    }

    /*
     * Only way found to call panel-bridge post_disable &
     * panel unprepare before the dsi "final" disable...
     * This needs to be fixed in the drm_bridge framework and the API
     * needs to be updated to manage our own call chains...
     */
    if (dsi->panel_bridge->funcs->post_disable) {
        dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge);
    }

    if (dsi->slave) {
        dw_mipi_dsi_disable(dsi->slave);
    }

    dw_mipi_dsi_disable(dsi);
}

static unsigned int dw_mipi_dsi_get_lanes(struct dw_mipi_dsi *dsi)
{
    /* this instance is the slave, so add the master's lanes */
    if (dsi->master) {
        return dsi->master->lanes + dsi->lanes;
    }

    /* this instance is the master, so add the slave's lanes */
    if (dsi->slave) {
        return dsi->lanes + dsi->slave->lanes;
    }

    /* single-dsi, so no other instance to consider */
    return dsi->lanes;
}

static void dw_mipi_dsi_mode_set(struct dw_mipi_dsi *dsi, const struct drm_display_mode *adjusted_mode)
{
    const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
    void *priv_data = dsi->plat_data->priv_data;
    int ret;
    u32 lanes = dw_mipi_dsi_get_lanes(dsi);

    if (dsi->apb_rst) {
        reset_control_assert(dsi->apb_rst);
        usleep_range(0xa, 0x14);
        reset_control_deassert(dsi->apb_rst);
    }

    ret = phy_ops->get_lane_mbps(priv_data, adjusted_mode, dsi->mode_flags, lanes, dsi->format, &dsi->lane_mbps);
    if (ret) {
        DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");
    }

    pm_runtime_get_sync(dsi->dev);
    dw_mipi_dsi_init(dsi);
    dw_mipi_dsi_dpi_config(dsi, adjusted_mode);
    dw_mipi_dsi_packet_handler_config(dsi);
    dw_mipi_dsi_video_mode_config(dsi);
    dw_mipi_dsi_video_packet_config(dsi, adjusted_mode);
    dw_mipi_dsi_command_mode_config(dsi);
    dw_mipi_dsi_line_timer_config(dsi, adjusted_mode);
    dw_mipi_dsi_vertical_timing_config(dsi, adjusted_mode);

    dw_mipi_dsi_dphy_init(dsi);
    dw_mipi_dsi_dphy_timing_config(dsi);
    dw_mipi_dsi_dphy_interface_config(dsi);

    dw_mipi_dsi_clear_err(dsi);

    ret = phy_ops->init(priv_data);
    if (ret) {
        DRM_DEBUG_DRIVER("Phy init() failed\n");
    }

    if (phy_ops->power_on) {
        phy_ops->power_on(dsi->plat_data->priv_data);
    }

    dw_mipi_dsi_dphy_enable(dsi);

    dw_mipi_dsi_wait_for_two_frames(adjusted_mode);

    /* Switch to cmd mode for panel-bridge pre_enable & panel prepare */
    dw_mipi_dsi_set_mode(dsi, 0);
}

static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge, const struct drm_display_mode *mode,
                                        const struct drm_display_mode *adjusted_mode)
{
    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);

    dw_mipi_dsi_mode_set(dsi, adjusted_mode);
    if (dsi->slave) {
        dw_mipi_dsi_mode_set(dsi->slave, adjusted_mode);
    }

    DRM_DEV_INFO(dsi->dev, "final DSI-Link bandwidth: %u x %d Mbps\n", dsi->lane_mbps,
                 dsi->slave ? dsi->lanes * 0x2 : dsi->lanes);
}

static void dw_mipi_dsi_bridge_enable(struct drm_bridge *bridge)
{
    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);

    /* Switch to video/cmd mode for panel-bridge enable & panel enable */
    if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
        dw_mipi_dsi_set_mode(dsi, MIPI_DSI_MODE_VIDEO);
        if (dsi->slave) {
            dw_mipi_dsi_set_mode(dsi->slave, MIPI_DSI_MODE_VIDEO);
        }
    } else {
        dw_mipi_dsi_set_mode(dsi, 0);
        if (dsi->slave) {
            dw_mipi_dsi_set_mode(dsi->slave, 0);
        }
    }
}

static enum drm_mode_status dw_mipi_dsi_bridge_mode_valid(struct drm_bridge *bridge,
                                                          const struct drm_display_info *info,
                                                          const struct drm_display_mode *mode)
{
    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
    const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
    enum drm_mode_status mode_status = MODE_OK;

    if (pdata->mode_valid) {
        mode_status = pdata->mode_valid(pdata->priv_data, mode);
    }

    return mode_status;
}

static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
{
    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);

    if (!bridge->encoder) {
        DRM_ERROR("Parent encoder object not found\n");
        return -ENODEV;
    }

    /* Set the encoder type as caller does not know it */
    bridge->encoder->encoder_type = DRM_MODE_ENCODER_DSI;

    /* Attach the panel-bridge to the dsi bridge */
    return drm_bridge_attach(bridge->encoder, dsi->panel_bridge, bridge, flags);
}

static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
    .mode_set = dw_mipi_dsi_bridge_mode_set,
    .enable = dw_mipi_dsi_bridge_enable,
    .post_disable = dw_mipi_dsi_bridge_post_disable,
    .mode_valid = dw_mipi_dsi_bridge_mode_valid,
    .attach = dw_mipi_dsi_bridge_attach,
};

#ifdef CONFIG_DEBUG_FS

static int dw_mipi_dsi_debugfs_write(void *data, u64 val)
{
    struct debugfs_entries *vpg = data;
    struct dw_mipi_dsi *dsi;
    u32 mode_cfg;

    if (!vpg) {
        return -ENODEV;
    }

    dsi = vpg->dsi;

    *vpg->reg = (bool)val;

    mode_cfg = dsi_read(dsi, DSI_VID_MODE_CFG);

    if (*vpg->reg) {
        mode_cfg |= vpg->mask;
    } else {
        mode_cfg &= ~vpg->mask;
    }

    dsi_write(dsi, DSI_VID_MODE_CFG, mode_cfg);

    return 0;
}

static int dw_mipi_dsi_debugfs_show(void *data, u64 *val)
{
    struct debugfs_entries *vpg = data;

    if (!vpg) {
        return -ENODEV;
    }

    *val = *vpg->reg;

    return 0;
}

DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_mipi_dsi_debugfs_show, dw_mipi_dsi_debugfs_write, "%llu\n");

static void debugfs_create_files(void *data)
{
    struct dw_mipi_dsi *dsi = data;
    struct debugfs_entries debugfs[] = {
        REGISTER(vpg, VID_MODE_VPG_ENABLE, dsi),
        REGISTER(vpg_horizontal, VID_MODE_VPG_HORIZONTAL, dsi),
        REGISTER(vpg_ber_pattern, VID_MODE_VPG_MODE, dsi),
    };
    int i;

    dsi->debugfs_vpg = kmemdup(debugfs, sizeof(debugfs), GFP_KERNEL);
    if (!dsi->debugfs_vpg) {
        return;
    }

    for (i = 0; i < ARRAY_SIZE(debugfs); i++) {
        debugfs_create_file(dsi->debugfs_vpg[i].name, 0x1a4, dsi->debugfs, &dsi->debugfs_vpg[i], &fops_x32);
    }
}

static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi)
{
    dsi->debugfs = debugfs_create_dir(dev_name(dsi->dev), NULL);
    if (IS_ERR(dsi->debugfs)) {
        dev_err(dsi->dev, "failed to create debugfs root\n");
        return;
    }

    debugfs_create_files(dsi);
}

static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi)
{
    debugfs_remove_recursive(dsi->debugfs);
    kfree(dsi->debugfs_vpg);
}

#else

static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi)
{
}
static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi)
{
}

#endif /* CONFIG_DEBUG_FS */

static struct dw_mipi_dsi *_dw_mipi_dsi_probe(struct platform_device *pdev,
                                              const struct dw_mipi_dsi_plat_data *plat_data)
{
    struct device *dev = &pdev->dev;
    struct dw_mipi_dsi *dsi;
    int ret;

    dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
    if (!dsi) {
        return ERR_PTR(-ENOMEM);
    }

    dsi->dev = dev;
    dsi->plat_data = plat_data;

    if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps || !plat_data->phy_ops->get_timing) {
        DRM_ERROR("Phy not properly configured\n");
        return ERR_PTR(-ENODEV);
    }

    if (!plat_data->base) {
        dsi->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(dsi->base)) {
            return ERR_PTR(-ENODEV);
        }
    } else {
        dsi->base = plat_data->base;
    }

    /*
     * Note that the reset was not defined in the initial device tree, so
     * we have to be prepared for it not being found.
     */
    dsi->apb_rst = devm_reset_control_get_optional_exclusive(dev, "apb");
    if (IS_ERR(dsi->apb_rst)) {
        ret = PTR_ERR(dsi->apb_rst);
        if (ret != -EPROBE_DEFER) {
            dev_err(dev, "Unable to get reset control: %d\n", ret);
        }

        return ERR_PTR(ret);
    }

    dw_mipi_dsi_debugfs_init(dsi);
    pm_runtime_enable(dev);

    dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
    dsi->dsi_host.dev = dev;
    ret = mipi_dsi_host_register(&dsi->dsi_host);
    if (ret) {
        dev_err(dev, "Failed to register MIPI host: %d\n", ret);
        pm_runtime_disable(dev);
        dw_mipi_dsi_debugfs_remove(dsi);
        return ERR_PTR(ret);
    }

    dsi->bridge.driver_private = dsi;
    dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
#ifdef CONFIG_OF
    dsi->bridge.of_node = pdev->dev.of_node;
#endif

    return dsi;
}

static void dw_mipi_dsi_remove_func(struct dw_mipi_dsi *dsi)
{
    mipi_dsi_host_unregister(&dsi->dsi_host);

    pm_runtime_disable(dsi->dev);
    dw_mipi_dsi_debugfs_remove(dsi);
}

void dw_mipi_dsi_set_slave(struct dw_mipi_dsi *dsi, struct dw_mipi_dsi *slave)
{
    /* introduce controllers to each other */
    dsi->slave = slave;
    dsi->slave->master = dsi;

    /* migrate settings for already attached displays */
    dsi->slave->lanes = dsi->lanes;
    dsi->slave->channel = dsi->channel;
    dsi->slave->format = dsi->format;
    dsi->slave->mode_flags = dsi->mode_flags;
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi_set_slave);

/*
 * Probe/remove API, used from platforms based on the DRM bridge API.
 */
struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev, const struct dw_mipi_dsi_plat_data *plat_data)
{
    return _dw_mipi_dsi_probe(pdev, plat_data);
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);

void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
{
    dw_mipi_dsi_remove_func(dsi);
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);

/*
 * Bind/unbind API, used from platforms based on the component framework.
 */
int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder)
{
    int ret;

    ret = drm_bridge_attach(encoder, &dsi->bridge, NULL, 0);
    if (ret) {
        DRM_ERROR("Failed to initialize bridge with drm\n");
        return ret;
    }

    return ret;
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);

void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
{
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);

struct drm_connector *dw_mipi_dsi_get_connector(struct dw_mipi_dsi *dsi)
{
    return drm_panel_bridge_connector(dsi->panel_bridge);
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi_get_connector);

MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
MODULE_DESCRIPTION("DW MIPI DSI host controller driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:dw-mipi-dsi");
